You should be prompted to set a password again and use the verification code if you did not do it the first time. Just start AxCrypt.

And, yes, if you uninstall AxCrypt 2 you can re-install AxCrypt 1. If you have not opened the files with AxCrypt 2, they remain identical and unchanged, and can of course be opened with AxCrypt 1 if they could be opened before.